This invention is related to a joint for connecting a pair of conduits which pass either a liquid or a gas and require a high-degree of joint sealing integrity.
Internal combustion engine exhaust systems require a high degree of joint sealing integrity to satisfy federal standards. Such standards are expected to become particularly strict beginning with the 1996 models. Typically commercial joints comprise a pair of flat flanges welded around the conduit. A gasket is disposed between the flanges and fasteners clamp the two flanges together.
A variety of other types of joints are known in the prior art some of which use a spherical surface in the sealing structure between the two pipes. Other joints use a frusto-conical sealing surface, see for example, U.S. Pat. No. 1,641,839 which was issued on Sep. 6, 1927 to L. H. Cain, J. Hunter Brogan and Charles J. Brogan for "Tank-Hose Coupling"; U.S. Pat. No. 3,704,995 which issued on Dec. 5, 1972 to Theodore W. Hetherington for "Pipe Manifold Flange"; and U.S. Pat. No. 4,428,603 which issued Jan. 31, 1984 to Irwin H. Davlin for "Flange Union With Improved Metal-to-Metal Seals".